Linear polyester resins



Patented Dec. 8, 1953 LINEAR POLYESTER RESINS Peter Kass, Wilmington,Del., assignor toAtlas Powder Company, Wilmington, Del., a, corporationof Delaware No Drawing. Application October 14, 1950,

Serial No. 190,239 I 1 r v invention relates to polyester resins andmore particularly to thermoplastic pulverulent polyester resins whichare curable and which may be copolymerized with other polymerizablebodies.

15 Claims. (01. zoo-45.4) by In my copending application Serial No.92,746

wherein R is an alkylene radical-containing from 2 to 3 carbon atoms, Ais a2-alkylidene radical containing from'3 to 4 carbon atoms, m and nare each at least one, and the average sum of m and n is not over 3.

Now I have found that resins may be prepared which retain theadvantageous properties of my previously disclosed polyester resins andexhibit, in addition, improved characteristics, especially in'regard toresistance of the cured resin to distortion under heat, this advantageappearing both in the autopolymerizates and in copolymers of saidresins. with other polymerizablebodies such as styrene and diallylphthalate.

It is, therefore, an object of this invention to prov'idehigh melting,curable, linear polyester resins of high resistance to heat distortion.It is a further object to provide high melting, linear polyester resinswhich are compatible with and readily copolymerizable with styrene orother polymerizable monomer to yield heat resistant copolymers.

The above and other objects will become more apparent from the followingdescription of the invention and the appended claims.

I' accomplish the above objects by providing a polye'sterificationproduct of an ethene dicarboxylic acid and a'mixed diol consisting of amajor proportion of a diol conforming to the formula wherein the symbolshave the meanings hereinbefore ascribed to them and a minor proportionof a lower alkylene glycol.

The said ethene dicarboxylic acids are fumaric acid and maleic acid, andthe polyester resins of my present invention may be esters of either ofthese acids or a mixture of the two. Throughout this specification andin the appended claims the term dicarboxylic acids is to be understoodto include anhydrides of such acids where such anhydrides exist, andderivatives of such acids which yield dicarboxylic acid radicals underesterification conditions. 7 For example, lower alkyl esters of thedicarboxylic acids are full equivalents of the acids themselves forpurposes of this application.

Diols conforming to the formula cited above and usefulas the majorcomponent of the diols employed in preparing the improved resins of thepresent invention are fully described in my above mentioned copendingapplication, whereinmethods for their preparation are also indicated.-

Among such diolsI may mention specifically 2.2 di-(i-betahydroxyethoxy'phenyl) -propane, 2.2 di (4 hydroxy propoxy phenyl)-butane, the polyoxyethylene ether of 2-butylidene diphenol wherein bothphenolic hydroxyls are oxyethylated and the average number ofoxyethylene groups per mol is 2.6, the polyoxypropylene ether ofisopropylidene diphenol wherein both phenolic hydroxyls areoxypropylated and the average number of'oxypropylene groups per mol is2.5, and the like. l 1

The minor component of the mixed diols useful in preparing my improvedlinear polyester resins is a lower alkylene'glycol, preferred members ofwhich are selected from the group consisting of ethyleneglycol,diethylene glycol, propylene glycol and-dipropylene glycol. Mixtures ofthe said glycols may equally be employed. As

. the proportion of said glycol increases in the mixture the tendency isfor the resulting resins to have lower melting points and to be lessamenable to grinding and storage without blocking. Useful resins withinthe purview of the invention are obtained, however, when as much as 50mol per cent of the mixed diol is the said lower glycol. When as littleas 10mm per cent of the reacting diolis a lower'glycol the resins aresignificantly improved over comparable resins containing no glycol withrespect'to the sought for properties of improved resistance to heatdistortion of cured and at substantially atmospheric pressure to min- 1imize loss of the more volatile components by distillation, and finallymore strongly and'un'der' reduced pressure to drive'the:polyesterification to the desired extent. The melting point of the resinresulting from polyesterification of any given mixed diol-dicarboxylicacid system inaccordance With the invention rises progressively as thedegree of esterification proceeds. In order that the resulting productshall be hardand friable, I carry the esterification forward untilits-.melting point by; the ASTM Ball and-Ring Method is at leastPSO Cand preferably. until its -melting point is at "least'90 "-C.: Linearpoly esters; of' these highz-melting points arereadily obtained-'without -ca-rrying :th'e:-reaction to the r stage. correspondingtosuper polyestersof the fiber forming type;

I may, incertain-cases employ known esterification-catalysts to hasten;the esterificatio'n' a1= though I generally prefer to :carry out ther'e'action inthe absence of such catalyst to avoid'c'ontamination of thefinalresin with catalyst residue. Preferably, though not necessarily; :Iincorporate in the reaction mixture a small propolymerization inhibitorsuch;. for example,'- as hydroquinone; pyrogallol; or the like, to minimize:- -double bonda polymerizationduring esterificationr' Thepolyestersfsm formed have 1' acid: number's ranging -downtva-rdfrom-30,'- and'like th'e' pol'yes ters of myh'ereinbefore mentionedcopending application are hardand pulverulent at ordinary temperatures;autopolymeri'zable :when: heated" in .the 'presence of knowncuring=catalysts, miscible col, 380.0 gnfumaricacidand 0.85g.10f;hydIQ-i quinone were heated: together in a reactionvessel'providedwith continuousagitation and means of s'weepingacurrent-pf inertgas through and over theeharge. The ringredients'wereheated together at-:l-1-90 C. for- A hour and at- 215 22'0iClIfonan-additional 4% hour and at 235 2 4T)" "C. .for an additionalhour; A vacuum" of 5035mm. of mercury wasthen applied: and the reactioncontinued at 215-220 C. forabout. 15

minutes. The resulting productwasa-hard; fri k able, =clear,--tan-colored resinm-with a .melting point -(-AS'I-M.- Ball:and::Method). of 104-350, and-an acid-number-of 21;:

r II 6381' grams .of fumaric acid; :1335 gramsof-2.2

di-(4-beta hydroxyethoxy phenyl) propane, 92 grams of ethylene glycoland one gram of hydroquinone were charged into a reaction vessel,provided with continuous agitation and means for sweeping a current ofinert gas through and over the chargetw The=mixture was': reacted for15.5. hours; the temperature being brought up from to 185 C. during thefirst four hours, held at 185 C. for the next 5 hours, and finally heldat 185 C. under vacuum (pressure='7 millimeters'of'mercury) for 6.5hours. The resulting product :was ahard, friable, clear, tan-coloredresin with' a melting point of 100 C. and an acid numberfof 20.

' EXAMPLE III 800" grams of 2.2 di-(4-hydroxy propoxy phenyl) propane,404 grams of fumaric acid and 0.6 gram of hydroquinohe were heated in anagiztatedreactionyessel in a current ofinert .gasat 185%Cwfor 8.751hdursl 93. grams of propylene glycol-was then addedandithe' reaction.continuedflinarr inert atmo sphere for 5.25:hours at C. Vacuum Was thenapplied and the .tem-: perature .taken; to 200 -C.-. for: 3.75 hourstthe pressure being =10 .millimeters of mercury. .There resulted fromthis process a clear-, tame-colored resin, :hard and friahle-atroomtemperature. with a melting point-M1073 C. i p

The products of any of. the aboveheated --to curing temperatures.-withlgnowncuring-catalysts, such for example:at 200 G.- for. 2 minuteswith 2% of-benzoylperoxideintimatelydispersed in the resin,are-convertedto-insoluble-linfusible resinous materials. showingremarkably-highresistanceto 1 distortion :undenth'e. influence of heatand pressure.

The incorporation of additional reactants in minor proportions tomodifythe properties ofxthe resins does notdepart from the spirit of theinvention i provided: 1 the polyester: consists i :essen= tially; ofthereaction PIOdUCti'Of an fetlie'ne die carboxylic :acid; and the mixed*diol he'reinbefore described: .Ihusaminoraproportionsfof .theiethenedicarboxylic acid may be replacedwbyrzotherdi carboxylic acids :or' by rmono carboxylie 1 acids. Or, minor proportions of'theaalcoholacomporrent may -be replaced by other polyhydrieformonohysclric -alcohols.:- By zwayof .illustration, ca useful laminatingresin; 1 producing low viscosity? solu tionsin styrene is prepared by-replacing partiof the "diolaby the monohydric'beta 'p11enoizyethanolaccordingfto the following example.

EXAIVIPLE IV v v The following I amountsof. -.material':' were chargedinto a ,-5 1. flash lequipped. with stirrer andCOz m1et 2490.g. .22 di(4-hydroxy propoxy henyn propane, 124.2 g. .ethyleneglycol llfii) g.rumaric acid; 264 a ifitalphenoicythanol and 0.6 g. hyd r'oquinone.'I'h'ihikture was-reacted at -190'C. for 1.5 hours, at whichl'timethetemperature was raised to. 215-220 C. and the reaction. continued foratotal of 3 hours; I the temperature was=then raised to 235-240? .C; .andthe.reactionpontinued.for. a total-10f 7.5 hours. A vacuum. of 10. mm;pressure was then= -applied to. the reaction vessel; the temperaturewvasallowedto drop to- -2203.-C. and esterifica-tion was continued for 2hours at 2l5 -220 C. under vacuum.-. Iheproduct resultingfrom-there'action was a hard brittle, amber-colored resin with a M.=P.(Ball and Ring) of .90 C. I

The modified polyester resins-of:thepresentina vention areparticularly?useful ini moldingpow ders where they may be incorporatedwith inert fillers and other polymerizable components, such for example,as diallyl phthalate and. subjected to heat and pressure to yield moldedarticles of high strength and of excellent resistance to heatdistortion. Illustrating the copolymerization of a resin made inaccordance with the present invention with diallyl phthalate in themolding of a plastic disk is the following:

EXAMPLE V A molding compound was made by milling together on a two rollmill heated to about 200 F. thefollowing ingredients: 400 g. of theproduct obtained in Example I, 174 g. diallyl phthalate, 687 g. groundsilica filler (Novacite 325 mesh), 212 g. titanium oxide pigment(Titanox RC) 400 g. chopped glass strands 7/16", 11.4 g. zinc stearateand 23 g. tert-butyl perbenzoate. 17- gram portions of theresultingputty-like material were compression molded into disks under500 p. s. i. pressure, at 350 F. for a time of 30 seconds. The moldeddisks had good impact strength, good resistance to heat distortion andexcellent electrical properties.

Other copolymers employing the novel polyesters herein disclosed includethe resinous product comprising the copolymerization product of from 90%to of a polymerizable vinyl compound, and from 10% to 90% of theresinous esterification product, having a melting point of at least 90C., of 1,2 dicarboxy ethene with a substantially stoichicmetricallyequivalent quantity of a mixed diol consisting of from about 50 to about90 mol percent of a diol conforming to the formula hereinbefore defined,and from about 50 to about 10 mol percent of a glycol selected from thegroup consisting of ethylene, diethylene, propylene and dipropyleneglycols. Particular among such copolymers are those wherein the saidvinyl monomer is styrene and wherein the said resinous esterificationproduct is that from a mixed diol consisting of from 50 to 80 molpercent of 2,2 di- (4 beta hydrox ethoxy phenyl) -propane, and fromabout 50 to about mol percent of ethylene glycol. Also, there may benamed the copolymerization product of from 15% to of diallyl phthalatewith from 85% to 15% of the last said resinous esterification product.

What is claimed is:

1. A thermoplastic, curable resinous esterification product of1,2-dicarboxy ethene with a substantially stoichiometrically equivalentamount of a mixed diol consisting of from about to about 90 mol per centof a diol conforming to the formula wherein It represents an alkyleneradical of from 2 to 3 carbon atoms, A represents a 2-alkylidene radicalof from 3 to 4 carbon atoms, m and n are each at least one and theaverage sum of m and n is not over 3; and from about 50 to about 10 molper cent of a lower alkylene glycol; said product having a melting pointof at least 80 C.

2. A thermoplastic, curable resinous esterification product of1,2-dicarboxy ethene with a substantially stoichiometrically equivalentquantity of a mixed diol consisting of from about 50 to about 90 mol percent of a diol conforming to the formula mesa-oQ-s-O-omonn wherein Rrepresents an alkylene radical of from radical of from 3 to 4 carbonatoms, m and n are each at least one and the average Sum'of m and n isnotover 3; and from about 50 to about 10 mol per cent of a loweralkylene glycol selected from the group consisting of ethylene glycol,diethylene glycol, propylene glycol and dipropylene glycol; said producthaving a melting point of at least 90 C.

3. A thermoplastic, curable, resinous esterification product of1,2-dicarboxy ethene with a substantially stoichiometrically equivalentquantity of a mixed diol consisting of from about 50 to about mol percent of a diol conforming to the formula wherein R represents analkylene radical of from 2 to 3 carbon atoms, A represents a2-alkylidene radical of from 3 to 4 carbon atoms, m and n are each atleast one, and the average sum of m and n is not over 3; and from about50 to about 20 mol per cent of a lower alkylene glycol selected from thegroup consisting of ethylene glycol, diethylene glycol, propylene glycoland dipropylene glycol; said product having a melting point of at leastC.

4. A thermoplastic, curable, resinous esterification product of1,2-dicarboxy ethene with a substantially stoichiometrically equivalentquantity of a mixed diol consisting of from about 50 to about 80 mol percent of a diol conforming to the formula wherein R represents analkylene radical of from 2 to 3 carbon atoms, A represents a2-alkylidene radical of from 3 to 4 carbon atoms, m and n are each atleast one, and the average sum of m and n is not over 3; and from about50 to about 20 mol per cent of ethylene glycol; said product having amelting point of at least 90 C.

5. A thermoplastic, curable, resinous esterification product of1,2-dicarboxy ethene with a substantially stoichiometrically equivalentquantity of a mixed diol consisting of from about 50 to 80 mol per centof 2.2 di-(4 beta hydroxy ethoxy phenyl) -propane and from about 50 toabout 20 mol per cent of ethylene glycol; said product having a meltingpoint of at least 90 C.

6. A thermoplastic, curable, resinous esterification product of fumaricacid with a substantially stoichiometric quantity of a mixed diolconsisting of '75 mol per cent of 2.2 di-( i-beta hydroxyethoXy phenyl)-propane and 25 mol per cent of ethylene glycol; said product having amelting point of at least 90 C.

'7. A thermoplastic, curable, resinous esterification product of fumaricacid with a substantially stoichiometric quantity of a mixed diolconsisting of 50 mol per cent of 2.2 (ii-(4 hydroxy propoxy phenyl)-propane and 50 mol per cent of ethylene r glycol, said product having amelting point of at least 90 C.

8. A thermoplastic, curable, resinous esterification product of onemolar proportion of fumaric acid with a mixture of dihydric andmonohydric alcohols consisting of 0.7 molar proportion of 2.2 (ii-(4hydroxy prcpoxy phenyl)-propane, 0.2 molar proportion of ethyleneglycol, and 0.2 molar proportion of beta phenoxyethanol; said producthaving a melting point of at least 90 C.

9. The insoluble, infusible resinous product ob- 8polymerizatiomproduct. of. from 15% etou%--ot dia-llyl: phthalate' andfrom to 55%..of the product. of; claim 5.;

15; A thermoplastic, curablqresinous esterifi+ cation product: of1,2-dicarboxyethene-With a substantially stoichiometrically equivalentquantity of'a. mixed ,diol consisting of from about-50m 801m01-rpercentof 2.2 di -(4 hydroxy propoxy phenyD-propane and from about 50-ito20=m01 percent of ethylene. glycol; said product having a, melting pointof at least C."

PETERV KASS.

References Cited in the file 0f, thislpatent.

UNITED. STATES PATENTS Name Date Rothrock et a1 Mar.-2,;1948

Number

2. A THERMOPLASTIC, CURABLE RESINOUS ESTERIFICATION PRODUCT OF1,2-DICARBOXY ETHENE WITH A SUBSTANTIALLY STOICHIOMETRICALLY EQUIVALENTQUANTITY OF A MIXED DIOL CONSISTING OF FROM ABOUT 50 TO ABOUT 90 MOL PERCENT OF A DIOL CONFORMING TO THE FORMULA
 12. THE RESINOUS PRODUCTCOMPRISING THE COPOLYMERIZATION PRODUCT OF FROM 90% TO 10% OF APOLYMERIZABLE VINYL COMPOUND AND FROM 10% TO 90% OF THE PRODUCT OF CLAIM2.